Interface GremlinScriptEngineManager

The ScriptEngineManager implements a discovery, instantiation and configuration mechanism for
GremlinScriptEngine classes and also maintains a collection of key/value pairs storing state shared by all
engines created by it. This class uses the ServiceProvider mechanism to enumerate all the
implementations of GremlinScriptEngineFactory. The ScriptEngineManager provides a method
to return a list of all these factories as well as utility methods which look up factories on the basis of language
name, file extension and mime type.

The Bindings of key/value pairs, referred to as the "Global Scope" maintained by the manager is available
to all instances of @code ScriptEngine} created by the GremlinScriptEngineManager. The values
in the Bindings are generally exposed in all scripts.

This interface is based quite heavily on the workings of the ScriptEngineManager supplied in the
javax.script packages, but adds some additional features that are specific to Gremlin and TinkerPop.
Unfortunately, it's not easily possible to extend ScriptEngineManager directly as there certain behaviors
don't appear to be be straightforward to implement and member variables are all private. It is important to note
that this interface is designed to provide support for "Gremlin-enabled" ScriptEngine instances (i.e. those
that extend from GremlinScriptEngine) and is not meant to manage just any ScriptEngine instance
that may be on the path.